Flexible sandwich-shaped composite film with simultaneous double electrically conductive anisotropy, magnetism and dual-color fluorescence

Abstract

A flexible sandwich-shaped composite film endowed with the multifunctionality of double electrically conductive anisotropy, magnetism and dual-color fluorescence was designed and constructed by electrospinning. The novel sandwich-shaped composite film consisted of a Janus nanoribbon array with both green fluorescence and double electrically conductive anisotropy forming the first layer and two kinds of nanofiber non-arrays with magnetism and red fluorescence respectively forming the second and third layers. The three layers were closely combined one by one to form the novel multifunctional sandwich-shaped composite film. In the first layer, Janus nanoribbon comprised the conductive side and the insulating-fluorescent side was designed and utilized as a constructional and conductive unit to form Janus-type film with left-to-right structure and high conductive anisotropy. Anisotropic conduction existed on both the left and right parts of the Janus-type film and the conductive directions in the two parts were vertical, leading to the realization of double anisotropic electrical conduction. By regulating the amounts of Tb(BA)₃phen complex and conductive polyaniline (PANI), the fluorescent-conductive bifunctional properties of the film could be respectively regulated. For the second and third layers, the magnetic and fluorescent properties could be regulated by modulating the contents of Fe₃O₄ nanoparticles (NPs) and Eu(BA)₃phen, respectively. Furthermore, due to the novel sandwich structure, the properties of each layer of the whole film were relatively independent, while all properties were highly integrated into this exceptional film. The green fluorescence of the first layer and red fluorescence of the third layer were scarcely affected by the magnetic variation of the second layer and the red fluorescence of the third layer was not influenced by the PANI content of the first layer. More importantly, the design concept and manufacturing method for sandwich-shaped composite film provide a new and convenient approach for constructing other multifunctional films.